One day when he was a boy, Cody Bellinger slipped inside a batting cage with his father. Clay Bellinger spent parts of three seasons with the New York Yankees, which granted his eldest son access to areas designated only for those in pinstripes. Cody was kindergarten age but already treating the ballpark as his playground.

Inside the cage, Cody swung and he swung and he swung, his prowess drawing the attention of Derek Jeter, the iconic shortstop. Beneath his sleek exterior, Jeter wielded a wit sharper than a scythe. Jeter regarded the boy’s father, a grinder who spent a decade in the minor leagues. Then he turned back to the kid.

“Man,” Jeter said, “you didn’t get your swing from your dad.”

Blessed with the talent of a superstar and raised with his father’s grit, Cody Bellinger flashed a bashful grin as he recalled Jeter’s seal of approval. He wears that look often these days. He wore it while he rounded the bases two dozen times this season for the Dodgers. It was there when he credited salted caramel ice cream for his strength. When teammates used his bats hoping to siphon some talismanic power. And during a television interview when he admitted he wasn’t sure who Jerry Seinfeld was.

Bellinger will wear that smile on Monday, when his father pitches to him in the Home Run Derby in Miami. And again on Tuesday when he represents the Dodgers and the National League in the All-Star game. In an organization famed for its young talent — the team brought Sandy Koufax and Fernando Valenzuela to the majors at 19, and Clayton Kershaw at 20 — Bellinger is the youngest All-Star in Dodgers history.

Bellinger turns 22 on Thursday. He was born six years, eight months and 23 days after Orel Hershiser threw a complete game to finish the 1988 World Series. In October, Bellinger will be crucial as the team tries to end a 29-year championship drought.

When he made his major league debut on April 25, the Dodgers owned a losing record. They will end the season’s first half on Sunday with the best record in the NL, steaming toward a fifth consecutive division title. Bellinger leads the team in home runs, runs batted in and slugging percentage. He required only 51 games to swat 21 homers — the fastest pace in baseball history. “After a game, when you’re laying in bed, you’re like, ‘Is this really happening?’ ” Bellinger said.

Manager Dave Roberts has called Bellinger the team’s savior. His teammates have described him as indispensable. He “rejuvenated” the Dodgers, third baseman Justin Turner said. His performance “lifted everybody else up,” second baseman Chase Utley said.

“His presence in the lineup was definitely needed,” fellow All-Star Kershaw said. “It helped stabilize us.”

To his best friends, the ones who’ve known him since he was a scrawny teen growing up outside of Phoenix, Bellinger’s sudden fame is more surreal than surprising. In the offseason, those friends — all ballplayers — often convene at the home of Patrick Murphy, one of Bellinger’s high school teammates and a pitcher in Toronto’s minor league system.

Everybody is like so surprised because he’s hitting all these homers, but look at his minor league stats. The kid hits homers. — Jamie Westbrook, regarding Cody Bellinger, whom he's known since middle school

Mark J. Terrill / Associated Press Cody Bellinger watches his two-run home run during Dodgers' game against the Pirates at Dodger Stadium on May 10. Cody Bellinger watches his two-run home run during Dodgers' game against the Pirates at Dodger Stadium on May 10. (Mark J. Terrill / Associated Press)

The guys pile onto the couch and watch sports. Bellinger usually grabs a pillow, sprawls on the floor and checks his phone. “We’re always just messing around, talking crap to each other,” Murphy said.

This past winter, Bellinger told his friends he couldn’t wait to get to the Show.

Shut up, bro, his buddies responded. You’re the No. 1 prospect.

“As the whole ‘Legend of Cody Bellinger' thing keeps taking off, I’m not even really surprised, because we’ve talked about it,” said Jamie Westbrook, a friend of Bellinger’s since middle school and a player in the Arizona Diamondbacks’ farm system. “Everybody is like so surprised because he’s hitting all these homers, but look at his minor league stats. What did you expect him to do? The kid hits homers.”

Clay Bellinger hit 12 homers over parts of four big-league seasons. He appeared in two games for the Angels in 2002, which was his last stay in the majors. His family accompanied him to New York, but also to minor league stops in Columbus, Salt Lake City and Fresno.

After games, Cody clung to his dad like a shadow, pestering him to throw batting practice. “That’s all he wanted to do when he was 4, 5, 6,” Clay said. “Hit and throw. Hit and throw. Hit and throw.”

The family settled in a suburb of Phoenix when Clay retired after the 2004 season. He joined the Gilbert Fire Department and found time for Cody and younger son Cole.

Clay coached Cody’s team when it reached the Little League World Series in 2007. Despite his pedigree and his zeal for the game, Cody did not emerge as a star until near the end of his high school career.

As a junior at Hamilton High, Bellinger grew beyond 6-feet tall. His body began to catch up to his violent swing, but he still produced more line drives than long balls. During his senior season, Bellinger hit only one home run. He felt the weight of expectation, stressed by the pressure of trying to improve his draft stock while facing opponents wary of throwing him hittable pitches. At one point, he sought advice from Mitch Nay, a teammate chosen by Toronto in the first round the year before.

“Your talent is going to show, no matter what,” Nay recalled telling Bellinger. “Don’t worry about it.”